I finally got a pair of convict cichlids. I know one of them is a female because of the more rounded fin and she has orange on her underside. The other one though im not sure of. He, i think, has a more flat head but the fins are sort of long, but i just cant tell. I got them home and their colors darkened completely. The black got much blacker and on the female her orange darkened too. They follow each other around the tank, and ever once in a while the one i think is a male will flare his gilles at her and she does the same back. They dont attack each other, or fight at all, just flare their gills. why do they do that?